Plate Tectonics Flashcards
Where are volcanoes usually found?
around the edges of tectonic plates, both on land and in the oceans
Where are tectonic plates found?
on top of a partially molten layer of rock called the asthenosphere
What is the theory of continental drift?
the continents were once united into a single supercontinent named Pangaea. He suggested that Pangaea broke up long ago and that the continents then moved to their current positions
Evidence that the continents where once together:
. the jigsaw fit
. the formation of coal
What is the jigsaw fit?
That continents look like they could “fit together” the best example of this would be North America & Africa
What is the coal formation?
Coal can inly be formed in hot, wet climates. This climate is found near the equator or in rainforests. But Antarctica has lots of coal but it does not have the right climate. Thai would suggest that Antarctica did once have the correct climate and must have moved over time away from the equator
What is a convection current?
A convection current is when a fluid, such as air or water, moves in a circular pattern because of differences in temperature and density.
How to plate tectonics move?
Plate tectonics move because of the movement of the Earth’s mantle. The mantle is made up of hot, molten rock that circulates in convection currents. These currents move the plates of the Earth’s crust, causing them to shift and collide.
The characteristics of destructive plate boundaries
A destructive plate boundary is where two tectonic plates collide and one plate is forced beneath the other into the Earth’s mantle. This can cause earthquakes and volcanic eruptions.
The characteristics of constructive plate boundaries
A constructive plate boundary is where two tectonic plates move away from each other, allowing magma from the mantle to rise up and create new crust. This can create new landforms such as volcanoes, underwater mountain ranges and earthquakes.
The characteristics of conservative plate boundaries
Conservative plate boundaries are where two plates slide past each other. The movement of the plates can cause earthquakes.
What happens where volcanoes form?
Where volcanoes form earthquakes always occurs
Do volcanoes form where earthquakes occur
No where earthquakes occur volcanoes don’t always form
Where is the greatest earthquake & volcano activity?
The greatest volcano & earthquake activity is around the pacific plate, knows as the ring of fire
What is the subduction zone?
This is where the oceanic crust is pushed down underneath continental crust at a destructive plate boundary
